Sensitive probing of temperature variations on nanometer scales represents an outstanding challenge in many areas of modern science and technology. A thermometer capable of sub-degree temperature resolution as well as integration within a living system could provide a powerful new tool for many areas of biological research, including the temperature induced control of gene expression, and the cell-selective treatment of disease.
The measurement of temperature on a microscopic length scale has emerged as a common challenge in many areas of science and technology. The ability to monitor sub-kelvin variations over a large range of temperatures can provide insight into both organic and inorganic systems, shedding light on questions ranging from tumor metabolism to heat dissipation in integrated circuits. Moreover, by combining local light-induced heat sources with sensitive nanoscale thermometry, it may be possible to engineer biological processes at the sub-cellular level. Some approaches that are currently being explored for this purpose include scanning probe microscopy, Raman spectroscopy, and fluorescence-based measurements using nanoparticles and organic dyes. These methods, however, are often limited by a combination of low sensitivity, bio-incompatibility, or systematic errors owing to changes in the local chemical environment.